[PATCH] Fix an assertion check

[Anoop C S]

On Tue, 2018-07-31 at 15:53 -0700, Jeremy Allison wrote:
> On Tue, Jul 31, 2018 at 02:59:05PM +0530, Anoop C S wrote:
> > On Mon, 2018-07-30 at 16:20 -0700, Jeremy Allison wrote:
> > > 
> > > Hmmm. Maybe. This code has been in use for over 10 years
> > > and hasn't caused an issue.
> > 
> > I came across this difference in assertion check while tracking down a
> > back trace from https://bugzilla.samba.org/show_bug.cgi?id=13439#c1.
> > The very same panic was also reported internally for us. Unfortunately
> > we do not have a reproducer in both cases. I have asked for further
> > debugging information and/or any steps to follow which might lead to
> > this assertion failure.
> > 
> > Meanwhile I am trying to figure out if some sequence of lock and unlock
> > requests(with specific offset and size) together with close can result
> > in this assertion failure situation with current code.
> > 
> > > I'm OK with fixing on next release cycle.
> 
> In that case I think I'm wrong, we should raise a bug
> and back-port. Sorry, didn't know you'd actually seen
> this as a real panic.

That's fine.

Still I cannot confirm on whether the current fix is enough to resolve the back trace mentioned in
the bug.

Please feel free to add your thoughts on possible cause for this panic situation.

Anoop C S.